Effect of meteorological factors on the development of lentil stemphylium blight at different sowing dates in rampur, chitwan, Nepal

Stemphylium species are pathogenic to a number of crops under broad geography and diverse environments. Stemphylium blight of lentil (Lens culinaris Medik) caused by Stemphylium botryosum Walr is becoming a serious emerging threat to lentil cultivation and become widespread throughout major legume growing areas in Nepal. Lentil was sown in different dates to observed incidence and severity of stemphylium blight in Rampur, Chitwan during two consecutive years 2012-2014. Lentil seeds sown up to middle of November escaped the disease severity and also resulted higher yield compared to other dates. Disease severity increased with the advancement of sowing date from November 1 to December 21 with decreased yields. The trends of disease development were similar in both years. The maximum and minimum temperatures, total rainfall and sunshine hour ranging from 22.42-24.23°C (mean 23.32°C), 4.12-13.00°C(mean 8.56°C), 9.6-30.5mm (mean 24.85mm) and 200.05-309.85 hour (mean 254.95 hour) respectively were favorable for disease development. A multiple linear regression model with temperature, rainfall and sunshine hourswas developed to predict stemphylium blight disease severity on lentil plants.